Re: Dinosaurs, Size, and Land Area

["Steve Salisbury" <steve_salisbury@bigpond.com>]

----------
>From: John Bois <jbois@umd5.umd.edu>
>Subject: RE: Dinosaurs, Size, and Land Area
>Date: Thu, 6 Dec 2001 6:12 AM

> On Wed, 5 Dec 2001 HPB1956@aol.com wrote:
>
>> "Dinosaur populations may have consisted mostly of posthatchling juveniles
..."
>
> One would think that crocs would be worth looking at here.  My
> understanding is that little crocs areculled fairly quickly.  meanwhile,
> large crocs are immune from predation and once in that size range, exist
> for a long time enabling a swelling of adult population.  Numbers, anyone?

I'd say crocs are what Greg Paul used for his dinosaur population 'models'.
Most croc populations are often segregated into various size cohorts, the
most prevalent separation being between juveniles and larger males.  The
ranges of nesting females and juveniles frequently overlap.  The main factor
contributing to dispersal appears to be agonistic interactions between
adults and growing juveniles; large crocs will often prey on
intermediate-sized animals and hatchlings.  As a result of this agonistic
behaviour, intermediate-sized animals are often excluded from areas they
were able to occupy when they were smaller, and take refuge in non-breeding
areas known as 'stockyards'.

Steve


---------------------------
Dr Steven Salisbury
Palaeontology and Geology, Queensland Museum
PO Box 3300, South Brisbane, Q 4101, Australia

email: steve_salisbury@bigpond.com
phone: +61 0407788660

http://www.Qmuseum.qld.gov.au/organisation/sections/PalaeontologyGeology/